>> it shows us somebody who is bold. unafraid. he said in one of our interviews, that gave him power. that gave him a sense of power. >> we asked him about his -- his interests. and he said it's more than an interest in kkg. it's an obsession. >> but why? ivins says it may have begun in college. 40 years ago. >> it goes back to him being rejected for a date by a woman at the university of cincinnati. he never could get over it. and he attributed her rejection of him to her membership in that sorority. >> to investigators, it now makes sense. the princeton, new jersey, mailbox. a few doors down from the kkg office. >> his obsession helps in my mind explain how the mailbox that was used was chosen. >> meeting for coffee with an acquaintance who is wired for the fbi, ivins denies being the anthrax killer. >> i have no clue how to -- how to make a bioweapon and i don't want to know. >> but at the same time, he admits to memory loss. ivins is falling apart. abusing prescription drugs and alcohol. >> 911, what's your emergency? >> march